Biomedical subjects
Publications and source records attributed to R Ferszt.
Cerebral angiography still remains the method of choice for the evaluation of cerebral vascular malformations--even in this day and age of CT. In rare cases, however, these conditions can be missed by angiography, whereas CT can provide important though not pathognomonic clues, with a definite diagnosis possible only by surgical exploration.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Focal brain edema limited to one cerebral hemisphere was produced by ultraviolet irradiation of the exposed cortex. Tissue water content was determined by the gravimetric method which allows microsampling. Therefore, the spread of edema around the small necrotic area could be mapped more precisely than by determination of dry weight which calls for larger samples. As early as 30 min following irradiation, hyperemia and swelling of the brain are observed under the operating microscope. This correlates with venous stasis, hyperemia, and broadened perivascular spaces around venules and large capillaries accompanied by a marked rise in the specific weight of the tissue. After 4 h an edema front can be observed spreading from the perinecrotic zone in which there is a marked rise in endothelial cell vesicular activity. Edema reaches maximum levels in the deep white matter at 48 h post irradiation with normalisation of the tissue water content after 96 h. The velocity at which the edema front spreads from the cortex to the periventricular area lies in the range of 0.25 mm/hr. Edema reabsorption coincides with signs of retrograde micropinocytosis in endothelial cells.
Explore the source record for details and available documents.
Focal vasogenic brain edema was induced by ultraviolet irradiation of the exposed cerebral cortex of 16 cats. In 5 animals horseradish peroxidase was intravenously injected at times varying from 30 min to 24 h following irradiation and allowed to circulate for 45 min. Fixation was carried out by perfusion and immersion with glutaraldehyde. The tissue, part of it incubated for peroxidatic activity, was treated for electron microscopy. The UV-irradiation leads to a shallow coagulation of the superficial cortex from which a wide zone of edematous tissue spreads to the deep white matter within 24 h. Arterioles, capillaries and venules of this zone show enhanced pinocytotic activity and a concurrent rise in permeability for horseradish peroxidase which is found in micro- and macropinocytotic vesicles, in tubular vesicle-like structures, in endothelial wall invaginations and apparently not membrane-bound. These changes are most pronounced in venules which after 48 h allow penetration of reaction product though the base membrane into the surrounding neuropil. There is no evidence for the penetration of tight junctions which appear intact.
A novel tissue disaggregation technique has been devised which permits the isolation of neurons with fairly extensive processes attached. Cortex is dissociated by aspiration through nozzles of decreasing size followed by agitation on a vortex mixer, rather than by the usual technique of forcing tissue through sieves. After each aspiration step, dissociated cells are separated from undisrupted tissue by coarse filtration and the latter is subjected to repeated treatment. This prevents unnecessary trauma to the free cells. After disruption is complete, small pieces of undisrupted tissue are removed from the cell suspension by floating on the foam created by degassing the suspension under vacuum. Cells are purified by conventional velocity-gradient centrifugation. This procedure has been applied successfully to fresh rat brain, with or without a preincubation with trypsin, frozen human brain and frozen bovine brain. The cell yields from rat brain were comparable to or better than, those obtained by other procedures (37 X 10(6) cells/g brain) while the purity was comparable. Cell yields from human brain were similar to those from rat brain but the purity was lower. The lowered particle purity of human and bovine cells can probably be attributed to the conditions of storage of the tissue and to trapping of free nuclei in the meshwork of dendritic processes. Values are given for the amount of protein, RNA and DNA per cell.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
In an electron microscopic study of brain biopsy material from a case with Creutzfeldt-Jakob disease intranuclear vacuoles containing membrano-vesicular structures were found. To our knowledge this finding has not been previously reported in human spongiform encephalopathies. It may represent a specific alteration associated with Creutzfeldt-Jakob disease, and suggests the possibility of nuclear infection.
We report the third case of intracerebral neurinoma in a patient with von Recklinghausen's disease, who died of recurrent subdural hematomas after head injury. A total of ten tumors were found in the brain. Both by histological and ultrastructural standards the multiple tumors resembled neurinomas. The pattern of positivity for S-100 and myelin basic protein indicated the Schwann cell origin of the tumors. The ultrastructural findings indicated Schwann cells and numerous areas showing a well defined basement membrane surrounding spindle-shaped neoplastic cells and other areas lacking basement membrane with Schwann cells embedded in collagen. The present case may be categorized as a mixed form of peripheral and central neurofibromatosis. It seems safe to assume that perivascular nerves are the site of origin of the tumors.